Fixes OPEN-5842 Bug bubbling up the costs when model is unsupported

Author: gustavocidornelas

openlayer/constants.py

@@ -78,6 +78,10 @@
         "input": 0.03e-3,
         "output": 0.06e-3,
     },
+    "gpt-4-turbo-preview": {
+        "input": 0.01e-3,
+        "output": 0.03e-3,
+    },
     "gpt-4-0125-preview": {
         "input": 0.01e-3,
         "output": 0.03e-3,

openlayer/tracing/tracer.py

@@ -176,9 +176,9 @@ def bubble_up_costs_and_tokens(
     def add_step_costs_and_tokens(step: Dict[str, Any]) -> Tuple[float, int]:
         step_cost = step_tokens = 0
 
-        if "cost" in step:
+        if "cost" in step and step["cost"] is not None:
             step_cost += step["cost"]
-        if "tokens" in step:
+        if "tokens" in step and step["tokens"] is not None:
             step_tokens += step["tokens"]
 
         # Recursively add costs and tokens from nested steps